AC Blower was not working so I went ahead and replaced the blower, assuming that was the issue since it is fairly common, but that did not fix it. I checked any fuses under the hood and under drivers side dash marked ac, heat, blower, etc. all were good. I found a troubleshooting guide with a flowchart for the blower motor. My question is where is the location of the AC Amplifier and the Blower Motor Controller?
The blower motor controller is the unit that failed on my 2004. Like you, I first changed the fan motor without result. It is located in the fan ducting downstream from the fan housing and wires lead from the controller to the blower motor. Look for a used unit on eBay if you want to save some $$ compared to a new unit price. The air conditioner amplifier is mounted on the center floor, below the radio. Remove the "instrument panel finish panel lower center" for access.
Thanks Patrick, much appreciated. I'm going to swap parts in from another Prius to see which, if either, is faulty.